Boris Johnson faces HS2 backlash in his Uxbridge constituency

Boris Johnson’s constituency could be swamped with anti-HS2 activists in the run-up to polling day after a government-commissioned review gave the green light to the contentious rail line.

Campaigners are preparing to ramp up their opposition following today’s leaked report which urges ministers to press ahead with the contentious project despite spiralling costs. 

The Prime Minister’s Uxbridge and South Ruislip seat is on the proposed London to Birmingham route, which is believed to be a cause for concern among voters. 

Stop HS2, the organisation campaigning for the project to be axed, reacted to today’s report with anger and told MailOnline it is considering ‘increased activity’ in Mr Johnson’s seat.

Protesters demonstrating against the rail line gather near Parliament – they are now preparing to ramp up their opposition following a government-commissioned report giving it the go-ahead

Asked if the group could drive its supporters to flock to Uxbridge, campaign manager Joe Rukin said: ‘After today it’s increasingly likely.   

‘We were always a bit sceptical about whether the report was an election gimmick, and today has shown that.

‘Now he doesn’t think that HS2 is important because he no longer faces the threat of the Brexit Party.

‘All of a sudden the report is released and the timing couldn’t stink more.’

‘He thinks the threat of him losing his seat is over.’

But Mr Rukin said that HS2 is an issue that can affect outcomes at the ballot box and than any candidate who dismisses it risks a ‘gross miscalculation’. 

He added that there is going to be ‘increased activity’ in Conservative seats along the railway line in the lead up to December 12, and suggested that – without revealing specific plans – the Prime Minister’s constituency could be among those targeted. 

Mark Keir, the local Green Party candidate and Extinction Rebellion demonstrator said that voters are concerned about HS2 ‘screwing up their flood defences’.

Extinction Rebellion stopped short of saying they were going to deploy activists to the constituency, but today whipped up their supporters against Mr Johnson by slamming the government for its supposed continuation of HS2.

The Prime Minister’s Uxbridge and South Ruislip seat is on the proposed London to Birmingham route and HS2 (artists impression pictured) is believed to be an issue cutting through with his voters

Extinction Rebellion and anti-HS2 protesters demonstrate outside the High Speed 2 headquarters at Euston Station in London in September

An XR spokesperson said: ‘Boris would be better off spending the HS2 budget on flood defences that includes restoring trees and nature, rather than spending it on a project that will destroy over 100 ancient woodlands in order to enable large-scale airport expansion, two of the worst things we can do in the face of our Climate and Ecological Emergency. 

Their warning came as the independently-led government review recommended ministers commit to the full proposed network connecting London, Birmingham, Manchester and Leeds.

The leaked document admits that it is ‘not affordable’ within the £56 billion budget set in the 2015 government spending review.

The document warns that without the high-speed rail link ‘large ticket prices’ would be needed to put people off travelling at peak times.

There are also no ‘shovel ready’ alternative investments that could be made in the existing network to provide for much-needed additional rail capacity.

But the report, written by Douglas Oakervee, the former HS2 chairman, does admit the project – the biggest infrastructure project in Europe – is ‘not affordable’ within the current budget, The Times reports.